How-To: Spark plug tube seals and cam cover

[Mitchy]

Today was the day to get on with some  necessary engine work.

 The 150,000-mile EJ202 has been stuttering at low revs and generally felt sluggish. The PO told me that the CEL light came on every so often due to the plugs needing renewal. I quietly wondered why he hadn’t done it.

 The leads are brand new NGK, and the distributor has been replaced by an aftermarket one. Luckily the original Hitachi remained in a box in the trunk so I have reinstalled that one.

I didn’t have to search for long to discover the spark plug problem.

 Oil on the lead boots is due to one thing; the plug tube oil seals in the rocker cover.

The plugs were in a state. No.2 cyl:

so here’s my process for changing the spark plugs and seals, and checking the valve clearance whilst the covers are off:

1. put the front wheels on blocks to get underneath.

2. Remove the under guard.

3. Remove the air intake assembly,  Battery and screen wash bottle.

4. Give the area a good washing as dirt must not enter the open heads.

5. I drained the oil. I believe it is not necessary, but I wanted to change it anyway.

6. I also removed the radiator fans and coolant overflow to gain access to the crank pulley, to be able to rotate the engine 90 degrees at a time for the valve clearance service.

 Now we are about ready to get on with the job...

 

Edited February 17, 2020 by Mitchy

[Mitchy]

7. Remove the m10 bolts from the rocker covers. There are 5 on the LH and 6 on the RH; the 6th is on the timing belt cover. It helps to be able to get underneath for some of them.

8. Remove the hose from the rocker cover. 
 

9. Place some cardboard beneath to catch the bit of oil retained in the rocker cover. Using a piece of wood and a mallet, gently tap the corners of the rocker cover and it slips off the head. I left the centre bolt in a few threads so the cover could not fall.

10. Wiggle it out as best you can. Mine came out with no force and some fancy maneuvering.

11. Set the bolts and cover to one side. Notice that there are three different bolt lengths on the RH cover.

Edited February 17, 2020 by Mitchy

[Mitchy]

Taking a short break, more to come...

[Mitchy]

12. Pull off the old, hardened and deformed tube seals, and compare them to your new set. No surprise they were leaking then. Gently remove the rocker cover gasket, and clean up the parts the best you can.

13. Now pull the plugs. This is where a UJ on the socket comes in handy. These old plugs were over-gapped at 1.4mm compared to the 1mm - 1.1mm recommended gap. They look like they have done 100,000 miles.

That and the heavy oiling probably explains the engine hesitation at low rev pulls.

[Mitchy]

14. This is where I deviate to set the valve clearance; 0.20mm intake, 0.25mm exhaust. 
With the LH timing cover removed, one will see that the LH camshaft pulley has an arrow. At the 12:00 position the valves for  #1 cylinder are closed, TDC. The valves needed a slight adjustment.

 Rotate the CRANK pulley clockwise as you look at it 90 deg so the arrow on the camshaft pulley faces the 15:00 position, and you have the #3 cylinder valves closed and ready for inspection. Repeat the 90 deg. steps in order (18:00 for #2 cyl., 21:00 for #4).

I inspected the timing belt as I am soon to be changing this too. Encouragingly it is a Subaru part, though I imagine it to have perhaps 150,000km. The car has 249,000 km, and asuming that the belt was serviced by Subaru at 100,000, I am unsure if it also had a Subaru service at 200,000. I have had the car for only the last 2000km!

 

Edited February 17, 2020 by Mitchy

[Mitchy]

15. Happy with the valves, now on to the reinstallation. 
Press the new tube seals onto their tubes, about 5mm until squarely seated.

16. Fit the new gasket into the  groove on the clean rocker cover. Note that the gasket has little ribs all around it. These aid the postioning of the gasket in its groove. You can just see the top of some of these ribs on the curves nearest to the camera.

17. Now wiggle the assembled cover back into position on the head. Be very careful not to nick or scrape the new rubber parts or aluminum sealing surfaces. Fit the bolts in their respective holes and tighten carefully to 5 NM.

**It is not a lot, 5 NM; those bolts are shouldered and once they butt up to the head they need very little extra tightening**
 

Inspect the plug tube seals to make sure they are not deformed.

 

 

[Mitchy]

18. Gap check and install the plugs. 

 To install the plugs I use a piece of rubber gas tube over a wide flathead screwdriver, and slip it over the neck of the plug. This way if you miss the thread the tube slips on the plug and does not force a crossed thread.

Once snug you can then tighten up to spec with your favorite socket/box spanner. 
In you go....

Press on the boots, and then fit everything else you removed.

Here is #4 plug, just to remind you of the urgency of this job:

As I removed the oil filler neck from the LH cover to aid removal and refitting, I replaced the O ring there too.

Remember to be clean, well-prepared, clean, methodical, clean, and do not rush.

I hope this helps some of you, I felt it was time to give a little back!

The low rev hesitation problem is completely sorted after this job, and the car runs and sounds better, including at idle. 

Thanks for looking   
 

 Mitchy

Edited February 17, 2020 by Mitchy

[brus brother]

thanks for posting

what did you use to clean the engine?

mine too is a mess.

 

[Mitchy]

I just sprayed some engine degreaser over the necessary areas, scrubbed and rinsed well.

 

[1 Lucky Texan]

great thread

no adhesive needed to hold the gaskets in place?

Edited February 18, 2020 by 1 Lucky Texan

[Mitchy]

I find that no sealant is necessary here, as per the original assembly and the Subaru tech service manual. The aluminum surfaces are in good clean condition, and the Subaru rubber is very good and squishable;

Gasket part #13294AA053 (L&R) for the EJ202 SOHC and others.

If you are asking if the sealant is needed to hold the gasket in the cover during assembly then the answer is ‘no’. The little ribs on the (OEM) gasket hold the gasket fast in the groove.

I should add that I have had mixed results with rocker gaskets;

The gasket (aftermarket) on my little 660cc Subaru Vivio leaked at the camshaft end caps after installation, so I opened it again and used a minimum of Victor Reinz ‘Reinzol’ .That stopped the leak dead. I do not know if it is holding as the car was sold on.
The Vivio also has a plastic rocker cover, and I noticed it was slightly deformed after 23 years, so sealant was indeed necessary, otherwise I’d have to source a long-discontinued rocker cover.

HTH

Edited February 18, 2020 by Mitchy

[brus brother]

anyone try the felpro gaskets with success??

[idosubaru]

On 2/18/2020 at 8:23 AM, brus brother said:

anyone try the felpro gaskets with success??

without reading through this entire thread - if you mean the valve cover and spark plug tube gaskets, yes.  i prefer OEM but i've used fel pro in the past on these EJ tube gaskets without any major issues.

[brus brother]

major issues?? I prefer no issues. Were there any? That drivers side looks like a real pain and I'd rather not have to revisit it.

[idosubaru]

18 hours ago, brus brother said:

major issues?? I prefer no issues. Were there any? That drivers side looks like a real pain and I'd rather not have to revisit it.

I haven’t seen enough install-to-leaking lifespans to say with certainty. anecdotally OEM seem less likely to leak years later. I think some high volume Subaru independents say that’s the case. I don’t have enough sample size to say correlation or causation, and maybe the differences are really small, but I favor OEM.

[Mitchy]

I have changed them on both Foresters; a ‘99 and an ‘00. I think as the originals last for 15-20 years then for the small additional cost I buy OEM again. 
I usually source oil seals and gaskets (which likely will only need renewing once) at the Subaru dealer as I know exactly what I am getting, and that there will be no surprises as far as fit and finish are concerned.

 

[brus brother]

Thanks all and thanks Mitchy for the tip on using the screwdriver wedged into the tubing to keep it on the straight and narrow when inserting spark plugs into the abyss. Great trick.